1. Field of the Invention
The present invention relates to an improved, magnetohydrodynamic (MHD) electric generator and to its use in a hybrid engine for converting the thermal energy of fuel and/or the thermal energy stored in air into electrical energy with a high thermodynamic efficiency and a high rate of energy conversion.
More particularly, the invention is concerned with an improvement to the MHD generator and hybrid engine disclosed in U.S. Pat. No. 4,500,803 issued on Feb. 19, 1985 in the name of the present inventor.
2. Brief Description of the Prior Art
The above mentioned U.S. Pat. No. 4,500,803 discloses a MHD generator wherein a gas flowing in a closed cycle is photoionized by a laser and passed through a magnetic field in order to produce electricity between a pair of electrodes that are perpendicular to the flow of gas and to the magnetic field, respectively. The laser used to photoionize the gas of the MHD generator is a gas-laser which combines a divergent nozzle to make the gas to laser by expansion, and a radio frequency generator to make the gas to laser by electric stimulation. The gas-laser also comprises an optical system for collecting the laser light and for focusing it on the flow of gas upstream the electrodes and magnetic field. This optical system includes a first pair of mirrors upstream and downstream the gas flow respectively, for focusing the laser light in the axial direction of the gas flow. It also includes an optical sub-system for collecting the laser light in a direction transversal to the gas flow and another pair of focusing mirrors for focusing the laser light collected by the sub-system in a direction transversal to the gas flow. A heat-exchanger is provided for heating the gas before it passes through the electrodes. A compressor is also provided for circulating the gas through the closed cycle.
U.S. Pat. No. 4,500,803 also discloses the combination of the above mentioned MHD generator with a conventional, open-cycle fuel engine. The resulting structure forms a hybrid engine for converting the thermal energy of a fuel and/or the thermal energy stored in air into electrical energy with a high thermodynamic efficiency and a high rate of energy conversion. In this particular combination, the open-cycle fuel engine comprises in series a combustion chamber through which air and fuel are burnt, the heat-exchanger of the MHD generator and a heat-engine for operating the compressor of the MHD generator.